jeannot



(No Model.) 4 Sheets- Sheet 1.

v. JEANNOT.

I STOP WATCH. v No. 378,592. Patented Feb. 28, 1888.

(.No Model.) 4 Sheets'Sheet V. JEANNOT.

STOP WATCH. I

No. 378.592 Patented Feb. 28, 1888.

Nv PETERS, Phnw-Lilhngrzphnr, \Vaihingion, D4 C (No Model.) 4-Sheets-Sheet 3.

' V. JEANNOT.

STOP WATCH.

N0. 3'78,592. Patented Feb. 28, 1888.

N. PETERS, F'hnwLilhogruphnr, Washington, 0. c.

(Nb'ModeL) 4 Sheets-Sheet 4.

. V. J EANNOT.

STOP WATCH.

Patented Feb. 28, 1888.

UNITED STATES- PATENT OFFICE.

VICTOR JEANNOT, OF GENEVA, SWITZERLAND.

STOP-WATCH.

SPECIFICATION forming part of Letters Patent No. 378,592, dated February 28, 1888.

Application filed September 29, 1887. Serial No. 251.003. (No model.)

To aZZ whom it may concern.-

Be it known that I, VIcroR J EANNOT, manufacturer at Geneva, in Switzerland, have invented a new and useful Improvement in Stop- WVatches, of which the following is a specification.

My invention consists of an instrument intended to be used by experimentalists,and not of a watch giving the hour and being provided with a stop-watch mechanism as accessory. All the stop-watches of the latter kind have proved to be liable to fail, the connection between the constantly-working movements of the watch and the periodically-working movements of the stop mechanism being of too delicate construction to produce an absolutely sure working of the stop-watch. Moreover, those stop-watches were not provided with an additional stop -watch mechanism, as is the case with the herein-described one. My new mechanism of stopwatch-which iscompleted by a mechanism adding several observations is constructed so as to give absolutely sure results of the observations made by the experimenters. With little modification of the gearings and of the dial the same mechanism may be employed as a tachometer or asa phonotelemeter, in View of measuring the speed of a railway train or to measure the distance between the station of a firing-battery and the observer.

My stop-watch and additional stop-watch mechanism are formed as a watch in which the face-dial marks the time of each experiment, while the back dial indicates the sum of time of several experiments.

In the accompanying drawings, Figure 1 shows the mechanism while at restthat is to say, having its three hands upon their starting-point-the stop watch mechanism as it would be seen when the face-dial is taken off.

' Figs. 2and 3 show the same mechanism in two other positions-Fig. 2 during its working, and Fig. 3 when stopped but before returning to 0. Fig. 4. shows the disposition of the face-dial covering said stop-watch mechanism. Fig. 5

the wheels of my stop-watch with additional stop-watch mechanism. Fig. 9 is a side View of the lever M, the plan view of which is to be seen in Figs. 1, 2, and 3. Fig. 10 is a crosssection through wheel N, and Fig. 11 a crosssection on an exaggerated scale through the heart cams, causing the returning back to 0 of the hands.

In all the figures similar letters refer to similar pieces.

For the purpose of well understanding the stop-watch mechanism it is necessary to explain at first the train of gearing which causes the motion of the three hands of the stop-watch, as well as of the three hands of the additional stop -watch mechanism. In both the stop mechanism and the additional stop mechanism there is a long hand turning about the center of the watch and showing the seconds and fifths of seconds, a short hand placed eecentrically and indicating the minutes, and another shorthand, also placed eccentrically and indicating the hours, (twelve ortwenty-four, at will.) The three hands of the stop-watch turn from left to right, those of the additional stopwatch mechanism from right to left.

a, Figs. 7 and 8, is the mainspring-barrel, the teeth of which are brought into gear with the pinion of the minute-wheel b, which makes one revolution in an hour, and the axis of which bears both the minute-hands B and B of the stop-watch and of the additional stopwatch mechanism. The wheel 1) drives the pinion of the second wheel, a, which is in gear with the third wheel, d, placed in the center of the watch, bearing the hands 0 and O, indicating the seconds and fifths of seconds, and making one revolution in a minute. The wheel (I is in gear with the pinion of the escapementwheel 6 which acts upon the balance-wheel f.

The axis of the mainspring-barrel bears a pinion, g, which is brought into gear with the hour-wheel h, the axis of which bears the two hour-hands Aand A of the stop-watch and of the additional stop-watch mechanism, and which makes one revolution in twelve hours or one revolution in twenty-four hours, according as one desires to have the one or the other division of time indicated upon the hour-dial. In the drawings I have supposed said dial divided so as to have the hour-hand making one revolution in twenty-four hours.

The wheels I and K are intended to cause the winding up of the mainspring. I is acted upon by a pinion, J, driven by means of the stem. The latter is provided with a click mechanism, so-called Breguet, Fig. 2. L is a click-spring preventing the turning back of wheel K.

As it appears from the foregoing description of the movements, the three hands of the stop-watch as well as the three hands of the additional stop-watch mechanism turn continuously together as long as the cscapement, and at the same time the spring-barrel, are not stopped. Therefore the beginning of working as well as the stopping of the stop-watch and additional stop-watch mechananism must be caused by putting into action and by stopping the eseapement-that is to say, the balancewheel. The returning back to 0 of the three stop-watch hands is caused by a mechanism distinct from the mechanism intended to cause the setting of the three hands of the additional stop-watch mechanism to 0.

From the general disposition of the mechanism just described it results that when the escapement is put into action the six hands A, A, B, B, O, and O are all put in motion at the same time and that when the escapement is stopped the six hands are stopped at the same time; but when the stop-watch hands are set to 0 the three hands of the additionalstop-watch mechanism remain where they have been stopped. There fore, when the escapement is again put into motion, the three hands of the additional stopwatch mechanism depart not from 0, but from the place of the dial where they have been stopped at last by stopping the stop-watch. At a second stoppage of the escapement the additional stop-watch mechanism will therefore indicate the sum of time of both experiments, and so on for several experiments made with the stop-watch. WVhen the whole-series of experiments is made, then the three hands of the additional stop-watch mechanism may also be brought back to 0 by means of a special push-piece, P.

Description of the mechanism intended to put into action and to stop the stop-watch and the additional stop watch mechcmzsm.-That double function is done by means of a lever, M, of a peculiar shape, acted upon by a spring, at. This lever is further acted upon by a cam, N, the shape of which is shown separately in Fig. 10. The lever M oscillates about the screw M, and is provided with apin, m,which traverses the plate, as shown in Fig. 9, and which bears against the periphery of the balance-wheel f when the lever M is in the position shown by Figs. 1 and 3. The cam N is acted upon by the click 0 of a double-armed lever, O, the one arm of which bears said click, the other one bearing a pusher, P, and being acted upon by a spring, 0. The cam N is provided at its periphery with fifteen clickteeth, in which successively engage the click 0, and with five vertical teeth, a, which successively act upon the levers M and R. The

cam N is turned from one tooth each time the push-piece is acted upon. vVhen the mechanism is placed in the position shown by Fig. 1, one of the extremities of face M" of the lever M bears against the vertical .tooth a of cam N. Thereby the pin m is maintained bearing against the periphery of the balance-wheel. If the cam N is turned from one tooth by pressing once upon the pusher P, the mechanism passes from the position shown in Fig. 1 into that of Fig. 2. The tooth n of cam N, leaving the face M of lever M, the latter falls into the space between a and n, and the hook M of lever M falls upon tooth n. During this fall of M the pin m describes an arc the center of which is the screw M, and which is tangential to the periphery of the balance-wheel, and therefore it gives to the latter an impulse and abandons then the same to itself. So the pressing down of the pusher P causes the sudden motion of the cscapement-that is to say, of the whole mechanism. This function is an absolutely sure one, the dcad-point being completely avoided. By a second pressure upon the pusher P the tooth n raises the hook M of lever M and bears upon one extremity of the face M, Fig. 3. In this position of the lever M the pin m leans again upon the periphery of the balance-w heel and stops the escapcment. A third pressure upon the pusher P causes the mechanism to pass from the position shown in Fig. 3 into that of Fig. 1. The tooth n slides along the face 1 of M, so as not to remove the latter from its foregoing position. During this slid ing of a upon Manother vertical teeth of the cam N causes the setting back to 0 of the three hands of the stop-watch, as hereinafter described.

Desortptton of the mechanism setting the hands of the stop-watch back to O.This function is made by means of a slide, Q, of peculiar shape, which acts at a time upon the heart-cams of the three hands of the stop-watch, A, B, and 0. Fig. 11 shows the manner in which the heart cams which hear those hands are connected to the corresponding axis. The spring it, affixed to the heart-cam Y, has its free end bearing upon a grooved part of the axis of said cam, and this spring prevents the heart-cam lifting and causes the heart-cam to turn with said axis. This arrangement insures the hands being turned with the axes which bear them, and at the same time permits of said hands being turned back to 0 after the rotation of their axes is arrested. The slide Q, sliding between the screws g on one side and the projection E of bridge E on the other side, is constantly pressed from left to right by the spring S. It is provided with three faces, 5, s, and s, which bear against the deepestpart of the heart-cams when the hands are to be set at 0. The screw 1' works as a catch to prevent the too vigorous striking of slide Q upon the axis bearing the hands. A bent lever, B, one arm of which is acted upon by the cam N, while the other one bears upon a pin, 19, fixed to slide Q, throws the latter successively into the three positions represented by Figs. 1, 2, and 3, according as one presses upon the pusher P, as above described. In Fig. 1 the slide Q maintains the but they are not set to when the hands ofthe stop-watch are set to 0, and the result of it is that they indicate the sum of the intervals of time indicated by the stop-watch by each experiment. It is, however, necessary that the hands of the additional stop-watch mechanism can be set to 0 when the series of experiments made with the stop-watch is finished and when another series is to be commenced. To that end the bridge H bears a slide, Q, analogous to the slide Q of the stop-watch and intended for the same purpose; but the slide Q takes only two positions-the position shown by full lines in Fig. 5 and the position shown by dotted lines in the same figure. The slide Q remains only as long in the position shown by dotted lines as one maintains the pusher P pressed down. The spring S tends to bring the slide Q back to its first position, in which it gives free passage to the heart-cams. The pusher P acts upon a spring, '1, oscillating about a screw, t, and bearing at the end of its flexible arm a small roller, t, which bears against a screw, T, fixed to the bridge H. When the pusher P is pressed down, the spring T is compressed until the roller 15 escapes from T and falls against the end of slide Q, driving the latter against the heart-cams and setting thereby the hands to 0. As in the mechanism of the stop-watch, there is a screw, r, intended to weaken the blow striking the axes of the hands.

Having thus described my invention, what I claim is 1. The combination, with the hands A B O, balance-wheel f, and gearing for actuating said hands and balance-wheel, of the cam N, lever M, pin in upon said lever, spring in, lever O, pawl o, and push-piece P, substantially as and for the purposes specified.

2. The combination, with the hands A B C, heart-cams on the arbors of said hands, balance-wheel f, and gearing for actuating said hands and balance-wheel, of the cam N, lever M, pin m upon said lever, spring in, lever O, pawl 0, push-piece P, slide Q, spring S, le ver B, and the stops 8, s, and 8 upon the slide S for returning the hands A B O to O,

substantially as set forth.

3. The combination, with the mechanism for operating the hands A B O, of the additional hands A B G upon the arbors of the hands A B C, respectively, separate heart-cams for said hands A B O, the slide Q, spring S, springlever T, and push-piece P, substantially as and for the purposes specified.

4. The combination, in a stop-watch, oftwo sets of hands, a train of gearing for driving both sets of hands simultaneously, mechanism for stopping both sets of hands simultaneously, and independent mechanism for returning either set of hands to 0, substantially as set forth.

vrcron JEANNOT. [1. s.]

Witnesses:

E. IMER SCHNEIDER, TH. WUERL. 

